You should send a formal offer of employment via post or email. With the letter of offer, you will need to include a copy of the Employment Contract and Position Description
To save time, you might want to call the candidate first to confirm that they are still interested in the position before sending the formal offer.
Don’t tell candidates that they haven’t been successful until your preferred candidate has formally accepted the offer of employment. Your first choice might get another offer or may not be able to accept the position for some reason. You may need to make an offer to your second choice.